Sheet trimmer



FIG. 1 is a perspective view of a sheet trimmer showing our new design;

FIG. 2 is a right side elevation thereof;

FIG. 3 is a front elevation thereof;

FIG. 4 is a left side elevation view thereof;

FIG. 5 is a rear elevation thereof; and,

FIG. 6 is a top plan view thereof.

The elements shown in broken lines form no part of the claimed design. 

The ornamental design for a sheet trimmer, as shown and described. 